ICES 2005/Theme Session N ICES CM 2005/N:16 The potential impact of commercial fishing activity on the ecology of deepwater chondrichthyans from the west of Scotland

Since the 1970s the deepwater shelf edge habitat west of the British Isles has been targeted by commercial fishers. The fishery is aimed at teleosts such as ling, black scabbardfish and roundnose grenadier. A smaller component of the catch is, however, composed of Chondrichthyes, i.e. the elasmobranchs (skates & rays) and holocephalans (chimaeras). Until the early 1990s these were discarded, but now they are either actively targeted or retained as by-catch and landed for human consumption. Elasmobranchs are particularly sensitive to high harvesting levels because of slow growth rates, high longevity and low fecundity. A recent combined assessment by ICES of the two most important commercial species, Centroscymnus coelolepis and Centrophorus squamosus indicated drastic decline to less than 50% original biomass. However, landings data are unreliable and fisheries independent, species-specific data that might be used to quantify the effects of fishing in these areas are sparse because of the technological challenges and expense involved in fishing to these depths. In this study, data from scientific deepwater trawl surveys collected by FRS Marine Laboratory were carried out from 1998-2004 and interrogated. These data were examined for any evidence of a decline in abundance and compared with published data from MAFF surveys in the same region between [1970][1971][1972][1973][1974][1975][1976][1977][1978]. Despite the short time series there were indications of declining trends in CPUE for a number of Squaliformes between 1998 and 2004 and the overall catch rates of sharks are dramatically lower than those recorded from pre-exploitation surveys in the 1970s. These results highlight the need to continue fisheries-independent surveys of this vulnerable ecosystem

A preliminary Investigation on Shelf Edge and Deepwater Fixed Net Fisheries to the West and North of Great Britain, Ireland, around Rockall and Hatton Bank.

Since the mid-1990s, a fleet of up to 50 vessels have been conducting a gillnet fishery on the continental slopes to the West of the British Isles, North of Shetland, at Rockall and Hatton bank. These vessels, though mostly based in Spain are registered in the UK, Germany and other countries outside the EU such as Panama. The fishery is conducted in depths between 200 and 1200 meters, with the main target species being monkfish (200-800 m) and deepwater sharks (800-1200m). These fisheries are not well documented or understood and they seem to be largely unregulated, with little or no information on landings, catch composition and discards. Vessels currently participating in the fishery are reported to use up to 250 km of gear, and the nets are left fishing unattended and hauled every 3-10 days with trip lengths varying between 4 –8 weeks. The amount of fishing gear used in the fisheries, the lengths of the fleets, and the fact that the nets are unattended much of the time, make it very likely that a large quantity of nets are lost, while there is also evidence of illegal dumping of sheet netting. The long soak times in these fisheries result in a high proportion of the catches being unfit for human consumption. Keywords: Deepwater Shark Fisheries, Ghostfishing

Demersal fish biodiversity: species-level indicators and trends-based targets for the Marine Strategy Framework Directive

The maintenance of biodiversity is a fundamental theme of the Marine Strategy Framework Directive. Appropriate indicators to monitor change in biodiversity, along with associated targets representing “good environmental status”, are required to be in place by July 2012. A method for selecting species-specific metrics to fulfil various specified indicator roles is proposed for demersal fish communities. Available data frequently do not extend far enough back in time to allow GES to be defined empirically. In such situations, trends-based targets offer a pragmatic solution. A method is proposed for setting indicator-level targets for the number of species-specific metrics required to meet their trends-based metric-level targets.JRC.G.4-Maritime affair